Device for rapidly moving an optical pick-up device in an optical reproducing apparatus to a desired position on a record disc

Abstract

A device for rapidly moving an optical pick-up device in an optical reproducing apparatus to a desired position on a record disc having a plurality of record tracks with an information signal recorded therein, includes a tracking error signal generating circuit for producing a tracking error signal corresponding to deviation of the pick-up device from the center of each record track; a drive device for moving the pick-up device in a direction transverse to the record tracks; and a track jump signal forming circuit for producing a track jump signal comprised of a drive signal followed by a brake signal, in response to the tracking error signal, the drive signal having a duration corresponding to the number of tracks traversed by the pick-up device and the brake signal having a duration corresponding to the speed of movement of the optical pick-up device in traversing the tracks, and for supplying the track jump signal to the drive device to control the latter to rapidly move the optical pick-up device in a direction transverse to the record tracks to the desired position.

We claim: 
     
       1. A device for rapidly moving pick-up means of an information signal reproducing apparatus to a desired position with respect to a record disc having at least one record track with an information signal recorded therein, comprising: drive means for moving said pick-up means in a direction transverse to said at least one record track; and   track jump means for producing a track jump signal comprised of a drive signal of a first duration followed by a brake signal of a second duration and for supplying said track jump signal to said drive means to control the latter to rapidly move said pick-up means in said transverse direction to said desired position, said track jumps means including speed detector means for detecting the speed of movement of said pick-up means relative to said disc during said second duration and timing means for determining the length of said second duration by terminating said brake signal in accordance with the detected speed of movement.   
     
     
       2. A device according to claim 1, further comprising tracking error means for producing a tracking error signal corresponding to a deviation of said pick-up means with respect to each said record track, and wherein said speed detector means detects said speed in response to said tracking error signal. 
     
     
       3. A device according to claim 2, wherein said timing means terminates said brake signal when said detected speed is less than a predetermined value. 
     
     
       4. A device according to claim 2, wherein said tracking error means produces said tracking error signal as a width modulated signal with cycles having widths proportional to the speed of said pick-up means relative to said disc, and wherein said speed detector means detects said speed by comparing the width of a portion of each cycle of said tracking error signal with a predetermined width. 
     
     
       5. A device according to claim 4, wherein said portion is a full cycle of said tracking error signal. 
     
     
       6. A device according to claim 4, wherein said portion is a half cycle of said tracking error signal. 
     
     
       7. A device according to claim 4, wherein said timing means terminates said brake signal when the width of said portion of a cycle is greater than said predetermined width. 
     
     
       8. A device according to claim 4, wherein said timing means includes clock pulse generating means and counter means for counting the number of said clock pulses during each of said cycles, said timing means producing an output signal for terminating said brake signal when a counted value of said counter means exceeds a predetermined value. 
     
     
       9. A device according to claim 2, further comprising switch means for normally supplying said tracking error signal to said drive means and for supplying said track jump signal in place of said tracking error signal during said durations of said drive signal and said brake signal. 
     
     
       10. A device according to claim 1, wherein said timing means terminates said brake signal when said detected speed is less than a predetermined value. 
     
     
       11. A device according to claim 1, further comprising counter means for counting the number of said record tracks traversed by said pick-up means as it is moved in said transverse direction during the first duration, wherein the length of said first duration is determined in accordance with a counted value of said counter means.